I'm working on a spring-boot (1.4.0-RELEASE) MVC Groovy app which will present an XML api. By default Spring seems to wire up Jackson which marshalls my response objects to JSON, however I want it to default to responding in XML without requiring any Accept header from clients, hence I configured the default content type as follows:
#Configuration
class SpringWebMvcConfig extends WebMvcConfigurerAdapter {
#Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
configurer.defaultContentType(MediaType.APPLICATION_XML);
}
}
This works just fine, however when running our tests I discovered that calling /health now returns a 406 status code and no content (it previously returned a 200 and a JSON response).
Having reverted the above change I thought perhaps I could force each controller to explicitly set the response content type via the use of a ResponseEntity, in doing so I tried the following in my controller method:
#RequestMapping(value = "/blah",
method = RequestMethod.GET)
ResponseEntity<MyResponseObject> getProgrammeRestrictions(#PathVariable String coreNumber) {
// Generate response object (code snipped)...
new ResponseEntity<MyResponseObject>(myResponseObject,
new HttpHeaders(contentType: MediaType.APPLICATION_XML),
HttpStatus.OK)
}
However this doesn't seem to influence the response type, which still defaults to JSON.
In a nutshell it seems that setting a default non-json content type breaks the actuator healthcheck. Is there someway to force the healthcheck bits and bobs to disregard the default setting and always be generated in JSON?
Has anyone else experienced this? Grateful for any pointers as I'm a bit stuck here.
Many thanks,
Edd
You need to add jackson-dataformat-xml dependency:
<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-xml</artifactId>
</dependency>
Then, make its XmlMapper available:
#Autowired
private MappingJackson2XmlHttpMessageConverter mappingJackson2XmlHttpMessageConverter;
#Bean
public ObjectMapper objectMapper(){
// this returns an XmlMapper, which is a subclass of ObjectMapper
return mappingJackson2XmlHttpMessageConverter.getObjectMapper();
}
It works when sending a request from the browser (http://localhost:8080/health), the returned result is in XML (chrome sends the header Accept: */*).
When sending the request programmatically, you still have to pass Accept: application/json in your header since the service expects this media type, but the returned result will be XML.
Related
I have the following resource that consumes a JSON being mapped to a POJO.
#Path("example")
public class ExampleResource {
#POST
#Consumes(MediaType.APPLICATION_JSON)
public Response addThesis(MyObject myObject) {
return Response.ok().entity("Test").build();
}
}
Here's the POJO class:
public class MyObject {
private String title;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
When I send a POST request with the body {"title":"Test title"} everything works fine. The response is Test, as expected. However, when I change the request to {"titlee":"Test title"} the server replies with this:
Unrecognized field "titlee" (class com.my.package.MyObject), not marked as ignorable (one known property: "title"])
at [Source: org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream#6dc6a46a; line: 2, column: 11] (through reference chain: com.my.package.MyObject["titlee"])
Obviously this is an exception thrown and returned by Jersey. How can I intercept this exception and return a custom status code and message?
What I've tried so far is to implement my own ExceptionMapper:
#Provider
public class MyJsonExceptionMapper implements ExceptionMapper<JsonProcessingException> {
public Response toResponse(JsonProcessingException e) {
return Response.status(400).entity("JSON Processing Error").build();
}
}
Unfortunately the response stays the same. When I implement an ExceptionMapper for a custom exception and throw the corresponding exception in the resource method though, everything works fine. I assume this has to do with the default ExceptionMapper for JsonProcessingException overriding my own one. Then I tried to create a generic mapper ("implements ExceptionMapper"), but again no success.
I've looked literally everywhere and tried many things including extending ResourceConfig and registering my mapper, but nothing has worked so far.
Some more information that might help to narrow the problem down: I am using Grizzly2 as the HTTP server which I am deploying as a Fat JAR.
The dependency part of my pom.xml looks like this:
<dependencies>
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-json-jackson</artifactId>
<version>2.24</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-grizzly2-http</artifactId>
<version>2.24</version>
</dependency>
</dependencies>
Any advice is highly appreciated.
Ok, this is dumb and hack-ish, but worked for me:
register(JacksonJaxbJsonProvider.class);
This is due to the following "nice default behavior" in the Jackson feature entry point:
if (!config.isRegistered(JacksonJaxbJsonProvider.class)) {
// add the default Jackson exception mappers
context.register(JsonParseExceptionMapper.class);
context.register(JsonMappingExceptionMapper.class);
:(
But, I'd still prefer an answer that fixes the problem "for real" - ie. without pre-registering components so that the feature cannot configure them properly...
I also faced this issue. If JacksonFeature is registered, you can simply register JacksonJaxbJsonProvider as a workaround.
When the JacksonFeature is in the classpath, it is automatically discovered by Jersey. Another approach to fix it is disabling auto discovery by setting ServerProperties.FEATURE_AUTO_DISCOVERY_DISABLE to true. As a result of this, you would need to register other features manually.
Alternatively you can get rid of the jersey-media-json-jackson artifact and use jackson-jaxrs-json-provider instead. With this, you will get rid of JacksonFeature and then you can register your own exception mappers.
One last option and probably what seems to be the correct solution (as pointed in Kysil Ivan's answer) you can write your own exception mapper and then give it a high priority, such as 1. If you use auto discovery, just annotate it with #Provider and #Priority:
#Provider
#Priority(1)
public class JsonParseExceptionMapper implements ExceptionMapper<JsonParseException> {
...
}
If you manually register your provider, you can give your provider a binding priority:
#ApplicationPath("/")
public class MyResourceConfig extends ResourceConfig {
public MyResourceConfig() {
register(JsonParseExceptionMapper.class, 1);
}
}
See this answer for more details.
We use JAX-RS on Wildfly to implement our web services and use the following to accomplish what you are trying to do with Jersey on Glassfish. Maybe it has similar features which you could look up. Our steps are:
The service is a stateless EJB, use EJB interceptor to trap exception
and populate request scoped object with details
Implement a PostProcessInterceptor which reads from request scoped object and modifies response before service returns. (This is specific to JAX-RS)
I have a spring boot application and am testing integration test. My REST service produces JSON and I can confirm it when testing it in postman.
But when I make a getForObject call by restTemplate:
#Test
public void testGetObject() {
Pet pet = restTemplate.getForObject("http://localhost:9000/pets/10000", User.class, Collections.emptyMap());
assertThat(pet.getName(), is("Bobby"));
}
It fails with following error:
Could not extract response: no suitable HttpMessageConverter found for response type [class petstore.entity.User] and content type [text/html;charset=utf-8]
I read lots of posts in stackoverflow, and having that restTempalte itself has MappingJackson2HttpMessageConverter as one of default converters which has JSON as default media type then I should not get this error.
Is there anything I am missing here?
Well, the message is pretty indicative - you're getting text/html as a response type, make your endpoint return application/json. If you're using Spring MVC then you can do it by adding the produces parameter to the annotation:
#RequestMapping(value = "/pets/{id}", method = RequestMethod.GET, produces = "application/json")
Or, if you're using Jersey, add this annotation to your method:
#Produces("application/json")
I have a Spring MVC 4 app with Spring Security 4 and is deployed on Tomcat 8 running under jdk 1.8. The web-service has the controller defined as such:
#RequestMapping(value = "/build", method = RequestMethod.POST, produces = "application/json", headers =
{ "Accept=*/*", "Content-Type=*/*" })
public SubjectEntity build(#RequestBody SubjectImportDTO subjectImportDTO)
{
Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
User user = null;
if (principal instanceof User)
{
user = ((User) principal);
}
SubjectEntity entity = service.build(subjectImportDTO);
System.out.println("FINISH: build");
return entity;
}
I am getting a csrf token, I have that setup correctly. I know the url is getting called correctly because I can see that in the logs when I get there. The service on the back-end is running, data is correctly entered into the database, I correctly get the write object, and using the Jackson Mapper, the object 'SubjectEntity' should be translated into JSON and sent back to the requesting client. This web-service has been unit tested under the Spring Web Test framework, and it works great!
So, I am familiar with an HTTP 404 error in not finding a URL when the wrong parameters are passed in, or you're trying to do a POST when it's a GET, etc. So many reasons why we can get a 404 error ...
BUT ... IN THIS CASE ... We've already gotten to the URL, executed the code, and then it has the data it needs. Since the Controller says we have content-type / and it produces application/json, I don't know what else could be wrong?
Any ideas?
You should add #ResponseBodyto your method. without this, Spring mvc tries to find another handler method which can send a response.
NB: #RestController automatically add #ResponseBody on each method in a controller.
When we configure Spring AOP the JSON Results disappear for : AOPExression1
<aop:pointcut id="dmhMethodExecution"
expression="within(com.aditya.dmh..*)" />
So I added an exclusion for : AOPExpression1 as AOpExpression2
<aop:pointcut id="dmhMethodExecution"
expression="within(com.aditya.dmh..*)
and !within(com.aditya.dmh.controller..*)" />
in the ASPECTJ Expression
Still I donot see my JSON results from the controller which is a restful implementation.
package com.aditya.dmh.controller;
#Controller
public class EmployeeController {
private EmployeeServiceInterface employeeService;
#Autowired
public void setEmployeeService(EmployeeServiceInterface employeeService) {
this.employeeService = employeeService;
}
#RequestMapping("/employeeservices/1/allemployees.view")
public #ResponseBody Result<EmployeeModel> getEmployees(){
return employeeService.getEmployees(0, 10);
}
}
When I use log4j for the DEBUG messages I see the following:
15:37:04.214 [http-8090-1] DEBUG o.s.web.servlet.DispatcherServlet - Null ModelAndView returned to DispatcherServlet with name 'dmhServiceDispatcher': assuming HandlerAdapter completed request handling
15:37:04.214 [http-8090-1] DEBUG o.s.web.servlet.DispatcherServlet - Successfully completed request
When I remove the AOP the JSON results start to appear and I see that the additional Debug Message.
17:11:36.270 [http-8090-2] DEBUG o.s.w.s.m.m.a.RequestResponseBodyMethodProcessor - Written [com.aditya.Result#8a85268] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter#62ba2e48]
Looking at the Spring forums I understand that the Convertor is automatically configured when the
<mvc:annotation-driven/>
is used.
Is my problem of configuring AOP have anything to do with the RequestResponseBodymethodProcessor not being called.
Does this have anything to do with the proxies created around my controller when I use AOPExpression1. Why would an exclusion as in AOPExpression2 still have the problem.
Anyhelp would be appreciated
I belive that to intercept a request to a controller you should do it with MVC interceptors and not with aspects. What I did is to put into the applicationContext.xml this:
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/employeeservices/1/allemployees.view"/>
<bean class="com.aditya.dmh.interceptor.ResultInterceptor" />
</mvc:interceptor>
</mvc:interceptors>
Now, the class ResultInterceptor is where you put the code you want to be done, for instance:
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
log.info("--- preHandle --- ");
return true;
}
At least this is the way I did it.
Hope it helps.
This is a bit of a speculation:
I think what is happening is a CGLIB based dynamic proxy is getting created for your controller (although you have excluded it explicitly in your new pointcut expression), if this happens then #RequestMapping annotations are not correctly detected(by `) and so the controller is not there to handle your REST request.
Can you try a few things:
Have an interface for the controller with the exact same methods that the controller handles, and put the #RequestMapping annotations there, this will handle cases where the dynamic proxy is created and should work as expected even if the dynamic proxy gets created..
Play around a little more with your pointcut expression to see why a proxy for you controller may be getting created.
THE SOLUTION FOR OUR PROBLEM IN THIS CONTEXT
We found out that the whole thing was with the Around Advice in AOP Configuration that we have had.
Before Fix
public void logAround(ProceedingJoinPoint joinPoint) throws Throwable {
long startTime = System.currentTimeMillis();
joinPoint.proceed();
long totalTime = System.currentTimeMillis() - startTime;
log.debug(buildLogMessage(new StringBuilder().append(METHOD_AROUND_ID)
.append("[").append(totalTime).append("] ").toString(),
joinPoint));
return returnValue;
}
After Fix
public Object logAround(ProceedingJoinPoint joinPoint) throws Throwable {
long startTime = System.currentTimeMillis();
Object returnValue = joinPoint.proceed();
long totalTime = System.currentTimeMillis() - startTime;
log.debug(buildLogMessage(new StringBuilder().append(METHOD_AROUND_ID)
.append("[").append(totalTime).append("] ").toString(),
joinPoint));
return returnValue;
}
the void effectively made sure that the Response Object sent by the logAround was not passed on back to the RequestResponseBodyMethodProcessor
Once we had it captured & returned the cglib proxies sent the response back to the processor & had the response sent back to the client.
I have a jersey client that I am trying to unmarshall a response entity with. The problem is the remote web service sends back application/octet-stream as the content type so Jersey does not know how to unmarshall it (I have similar errors with text/html coming back for XML and such). I cannot change the web service.
What I want to do is override the content-type and change it to application/json so jersey will know which marshaller to use.
I cannot register application/octet-stream with the json marshaller as for a given content type I actually might be getting back all kinds of oddities.
As laz pointed out, ClientFilter is the way to go:
client.addFilter(new ClientFilter() {
#Override
public ClientResponse handle(ClientRequest request) throws ClientHandlerException {
request.getHeaders().putSingle(HttpHeaders.CONTENT_TYPE, "application/json");
return getNext().handle(request);
}
});
I'm not well-versed in the Jersey client API, but can you use a ClientFilter to do this? Perhaps you could add a property to the request via ClientRequest.getProperties().put(String, Object) that tells the ClientFilter what Content-Type to override the response with. If the ClientFilter finds the override property, it uses it, otherwise it does not alter the response. I'm not sure if the ClientFilter is invoked prior to any unmarshalling though. Hopefully it is!
Edit (Have you tried something like this):
public class ContentTypeClientFilter implements ClientFilter {
#Override
public ClientResponse handle(ClientRequest request) throws ClientHandlerException {
final ClientResponse response = getNext().handle(request);
// check for overridden ContentType set by other code
final String overriddenContentType = request.getProperties().get("overridden.content.type");
if (overriddenContentType != null) {
response.getHeaders().putSingle(HttpHeaders.CONTENT_TYPE, overriddenContentType);
}
return response;
}
}
Under Java 8 and Jersey 2 you can do it with a lambda:
client.register((ClientResponseFilter) (requestContext, responseContext) ->
responseContext.getHeaders().putSingle("Content-Type", "application/json"));